Restaurants already source their materials and equipment from other suppliers. They don't grow their own food; they don't need to print their own menus.
Sure, the same is true of anything written. But much of that has shifted to digital media because it's more convenient. A print shop has much higher latency and change costs. The newer restaurants in my neighborhood mostly use flexible ways of conveying prices. QR codes, menus on big screens, chalkboards, or computer-printed paper menus on disposable paper.
More convenient for the restaurant, less convenient for the customer.
This defeats the whole purpose of a restaurant, which is to be convenient. If I wanted to be inconvenienced I would just buy groceries and cook them at home.
I don't think it's "the customer". I think it's you and some other folks who are in a relatively narrow customer niche who are very big on convenience and grew up on paper menus, making those feel convenient.
I'd add that the whole purpose of a restaurant isn't convenience for the customer. That's the purpose of going there for many customers, which should of course be honored. But the purpose of them for restaurateurs are generally on the order of "make an enjoyable living", which involves convenience for them too. As with almost anything social, the outcome must balance the desires of all involved.
